Abstract:The aims of the present study were to maximize the reduction of nitrogen loss from farmland and protect the main source of drinking water and stream water quality for Hexi reservoir. Site-specific observation was carried out in the present study, plots for nursery land with six fertilization management modes were selected, including broadcast placement (contrast), plastic mulching, straw mulching, setting buffer for planting grass around nursery land, band placement and hole placement, to explore the influence of different fertilization management mode on nitrogen losses in surface runoff and screen the best fertilization management mode in the catchment area of Hexi reservoir. The results showed that: under different fertilization management modes, the order of the concentration of annual nitrogen loss in the runoff was: broadcast placement (contrast)>plastic mulching>band placement>hole placement>setting buffer for planting grass around nursery land>straw mulching. The mean annual runoff load of total nitrogen from broadcast placement (contrast), plastic mulching, band placement, hole placement, setting buffer for planting grass around nursery land and straw mulching was 35.61, 18.30, 15.86, 12.94, 8.18, 3.44 kg/(hm2·a), respectively. The results indicated that hole placement, setting buffer for planting grass and straw mulching were better fertilization management modes, which would significantly reduce nitrogen runoff from non-point source output of nursery land and weaken the potential impact on water quality of Hexi reservoir by optimum combination of the above-mentioned better fertilization management mode in nursery land in the catchment area of Hexi reservoir in Changxing county. In addition, particulate nitrogen was the dominant form of nitrogen loss in the runoff, followed by nitrate nitrogen under all fertilization management modes. Furthermore, for the management mode of broadcast placement(contrast), plastic mulching, straw mulching, setting buffer for planting grass around nursery land, band placement and hole placement, annual loss of particulate nitrogen in the runoff accounted for about 69.11%, 68.87%, 68.04%, 61.89%, 61.17% and 65.09% of the total nitrogen losses, respectively; annual loss of nitrate nitrogen in the runoff accounted for about 23.18%, 23.36%, 20.21%, 27.20%, 32.02% and 28.71% of the total nitrogen losses, respectively.